Hypertension is a serious and quite common disease. Probably about twenty percent of the adult population may be affected by hypertension. It is further a major risk factor for the more serious cardiovascular diseases. Thus, control of hypertension is essential and it is most frequently carried out by drug therapy. However, it is known that some side effects are frequently encountered in drug therapy. This is more serious if the patient is suffering from some other disease such as diabetes. Thus, for example, care must be taken with diabetics if hydrazide, hydralazine or thiazide therapy is employed, in order to avoid serious consequences. Moreover, hydrazide therapy has been found to cause diabetes, which has been latent, to become manifest. It is desirable therefore that a drug be found which has a selective action in being positive toward diabetes and which thus may be employed for antihypertensive therapy for diabetic patients.